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A common inhibitory receptor for major histocompatibility complex class I molecules on human lymphoid and myelomonocytic cells.

Colonna M, Navarro F, Bellón T, Llano M, García P, Samaridis J, Angman L, Cella M, López-Botet M - J. Exp. Med. (1997)

Bottom Line: In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells.This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively.In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules.

View Article: PubMed Central - PubMed

Affiliation: Basel Institute for Immunology, Basel CH-4005, Switzerland.

ABSTRACT
Natural killer (NK) cell-mediated lysis is negatively regulated by killer cell inhibitory receptors specific for major histocompatibility complex (MHC) class I molecules. In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells. This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively. In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules. These results suggest that diverse leukocyte lineages have adopted recognition of self-MHC class I molecules as a common strategy to control cellular activation during an immune response.

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Diversity of the  extracellular region of ILT5. 15  variants of ILT5 were identified  from a pool of bone marrow  cells derived from 51 donors,  while only 1 variant (clone  DC.1) was detected from a single  donor. Amino acid variants are  clustered in variable regions (underlined). ILT5-cl41 is prematurely truncated as a consequence of an alternative splicing  which generates a stop codon.  D1–D4, extracellular domains.
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Figure 10: Diversity of the extracellular region of ILT5. 15 variants of ILT5 were identified from a pool of bone marrow cells derived from 51 donors, while only 1 variant (clone DC.1) was detected from a single donor. Amino acid variants are clustered in variable regions (underlined). ILT5-cl41 is prematurely truncated as a consequence of an alternative splicing which generates a stop codon. D1–D4, extracellular domains.

Mentions: Analysis of structural variability of ILT2, ILT4, and ILT5 in the population revealed that ILT5, as compared to ILT2 and ILT4, is characterized by a striking diversity. Amplification and sequencing of ILT5 cDNA from a pool of cells derived from different individuals yielded 15 distinct cDNAs, whereas only 1 ILT5 cDNA clone was amplified from a single donor. This result suggests that ILT5 may be extensively polymorphic, with amino acid variants clustered in several distinct regions of the extracellular domains (Fig. 10). Genomic studies will be required to establish whether all of the cloned ILT5 variants are encoded by different alleles of the same locus, or by different loci. We also identified 6 alternatively spliced forms of ILT4 and ILT5 cDNAs, some of which encode glycoproteins with a short cytoplasmic tail that lacks ITIMs, and one cDNA, termed ILT6, which lacks transmembrane and cytoplasmic regions, and may encode a soluble receptor. (ILT4, ILT5, and ILT6 cDNAs are available from EMBL/ GenBank/DDBJ under the following accession numbers: ILT4-cl1, AF000574; ILT4-cl17, AF011566; ILT4-cl26, AF011565; ILT5-cl16, AF000575; ILT5-cl17.6, AF009634; ILT5-cl17.7, AF009635; ILT5-cl17.8, AF009636; ILT5-cl17.10, AF009632; ILT5-cl17.11, AF009633; ILT5-cl19, AF009637; ILT5-cl22, AF009638; ILT5-cl31, AF009639; ILT5-cl33, AF009640; ILT5-cl36, AF009641; ILT5-cl40, AF009642; ILT5-cl41, AF009644; ILT5-cl6, AF009643; ILT5-cl17.18, AF031554; ILT5-cl17.23, AF031555; ILT5-cl17.30, AF031556; ILT5-clDC.1, AF031553; and ILT6, AF014923.


A common inhibitory receptor for major histocompatibility complex class I molecules on human lymphoid and myelomonocytic cells.

Colonna M, Navarro F, Bellón T, Llano M, García P, Samaridis J, Angman L, Cella M, López-Botet M - J. Exp. Med. (1997)

Diversity of the  extracellular region of ILT5. 15  variants of ILT5 were identified  from a pool of bone marrow  cells derived from 51 donors,  while only 1 variant (clone  DC.1) was detected from a single  donor. Amino acid variants are  clustered in variable regions (underlined). ILT5-cl41 is prematurely truncated as a consequence of an alternative splicing  which generates a stop codon.  D1–D4, extracellular domains.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199153&req=5

Figure 10: Diversity of the extracellular region of ILT5. 15 variants of ILT5 were identified from a pool of bone marrow cells derived from 51 donors, while only 1 variant (clone DC.1) was detected from a single donor. Amino acid variants are clustered in variable regions (underlined). ILT5-cl41 is prematurely truncated as a consequence of an alternative splicing which generates a stop codon. D1–D4, extracellular domains.
Mentions: Analysis of structural variability of ILT2, ILT4, and ILT5 in the population revealed that ILT5, as compared to ILT2 and ILT4, is characterized by a striking diversity. Amplification and sequencing of ILT5 cDNA from a pool of cells derived from different individuals yielded 15 distinct cDNAs, whereas only 1 ILT5 cDNA clone was amplified from a single donor. This result suggests that ILT5 may be extensively polymorphic, with amino acid variants clustered in several distinct regions of the extracellular domains (Fig. 10). Genomic studies will be required to establish whether all of the cloned ILT5 variants are encoded by different alleles of the same locus, or by different loci. We also identified 6 alternatively spliced forms of ILT4 and ILT5 cDNAs, some of which encode glycoproteins with a short cytoplasmic tail that lacks ITIMs, and one cDNA, termed ILT6, which lacks transmembrane and cytoplasmic regions, and may encode a soluble receptor. (ILT4, ILT5, and ILT6 cDNAs are available from EMBL/ GenBank/DDBJ under the following accession numbers: ILT4-cl1, AF000574; ILT4-cl17, AF011566; ILT4-cl26, AF011565; ILT5-cl16, AF000575; ILT5-cl17.6, AF009634; ILT5-cl17.7, AF009635; ILT5-cl17.8, AF009636; ILT5-cl17.10, AF009632; ILT5-cl17.11, AF009633; ILT5-cl19, AF009637; ILT5-cl22, AF009638; ILT5-cl31, AF009639; ILT5-cl33, AF009640; ILT5-cl36, AF009641; ILT5-cl40, AF009642; ILT5-cl41, AF009644; ILT5-cl6, AF009643; ILT5-cl17.18, AF031554; ILT5-cl17.23, AF031555; ILT5-cl17.30, AF031556; ILT5-clDC.1, AF031553; and ILT6, AF014923.

Bottom Line: In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells.This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively.In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules.

View Article: PubMed Central - PubMed

Affiliation: Basel Institute for Immunology, Basel CH-4005, Switzerland.

ABSTRACT
Natural killer (NK) cell-mediated lysis is negatively regulated by killer cell inhibitory receptors specific for major histocompatibility complex (MHC) class I molecules. In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells. This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively. In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules. These results suggest that diverse leukocyte lineages have adopted recognition of self-MHC class I molecules as a common strategy to control cellular activation during an immune response.

Show MeSH
Related in: MedlinePlus